Log transfer mechanism

ABSTRACT

A mechanism to stop and then selectively discharge logs serially advanced thereto comprises crescent shaped transfer elements mounted in laterally spaced relation and cooperating to form a cradle for receiving the logs. The presence of a first log in the cradle blocks the movement of additional logs to the cradle. Mechanism to rotate the transfer elements in unison turns the cradle to discharge a log therefrom and bumper members fixed to the transfer elements block the advance of additional logs to the cradle as the first received log is discharged from the cradle.

United States Patent [72] inventor Goerge W. Hartull Piqua, Ohio [21] Appl. No. 751,895 [22] Filed Aug. 12, 1968 [45] Patented June 15, 1971 [73] Assignee Hartzell Industries, Inc.

Piqua, Ohio [54] L06 TRANSFER MECHANISM 4 Claims, 3 Drawing Figs. 7 [52] 11.8. C1 198/26, 214/91 [51 Int. Cl. B65g 47/34 [50] Field of Search 198/26, 34, 25, 27; 214/1 R2 [56] References Cited UNITED STATES PATENTS 3,330,401 7/1967 Ahlstedt 198/22 X 3,355,042 11/1967 Mellottetal. 768,808 8/1904 Krumpelmann Primary Examiner-Harvey C. Hornsby Assistant Examiner-Alfred N. Goodman Attomey-Dybvig and Dybvig ABSTRACT: A mechanism to stop and then selectively discharge logs serially advanced thereto comprises crescent shaped transfer elements mounted in laterally spaced relation and cooperating to form a cradle for receiving the logs. The presence of a first log in the cradle blocks the movement of additional logs to the cradle. Mechanism to rotate the transfer elements in unison turns the cradle to discharge a log therefrom and bumper members fixed to the transfer elements block the advance of additional logs to the cradle as the first received log is discharged from the cradle.

LOG TRANSFER MECHANISM The present invention relates to log handling mechanisms, and more particularly to a mechanism for selectively transferring single logs from a log supply deck to a log carriage.

In sawmill operations in which logs are cut into planks, an individual log is loaded from a supply deck onto a log carriage, gripped by suitable log positioning devices on the carriage, and then the carriage reciprocated past a saw blade to successively remove planks from the log. After a first log has been cut into planks, the carriage is repositioned adjacent the supply deck where it receives a second log.

An object of the present invention is to provide a new and improved mechanism to selectively transfer logs from a supply deck to a log carriage.

Another object of the present invention is to provide, in association with a mechanism for transferring logs to a log carriage, means for blocking the advance of following logs during the period in which a single log is being transferred.

Still another object of the present invention is to so locate the log transfer mechanism that logs blocked in their advance to the transfer mechanism are blocked before they have left control of the supply mechanism which advances the logs to the transfer mechanism.

A still further object of the present invention is to so design the log transfer mechanism that it may be removably mounted upon a log supply deck, thus facilitating installation, repair and replacement of the transfer mechanism.

Other objects and advantages reside in the construction of parts, the combination thereof, the method of manufacture and the mode of operation, as will become more apparent from the following description.

In the drawing, FIG. 1 is a fragmentary plan view illustrating the present invention in association with a log supply mechanism.

FIG. 2 is a fragmentary section view taken substantially along the line 2-2 of FIG. 1 and schematically illustrating logs being handled with the aid of the present invention, phantom lines showing the direction in which a part of the invention moves.

FIG. 3 is also a fragmentary section view taken substantially along the line 2-2 of FIG. 1 and schematically illustrating a different operating position.

To facilitate adescription of the present invention, the invention is illustrated in association with a live deck assembly used to advance logs from right to left, as viewed in FIG. 1, for loading onto a log carriage, not shown. For loading a log, the log carriage is stopped along the left side of the deck assembly and a single log rolled from the deck assembly onto the carriage. The logs are supplied to the deck assembly from the right side, as viewed in FIG. 1, by any suitable mechanism, the details of which are unimportant to the present invention.

The deck assembly comprises three parallel beam assemblies a, 10b and 100 tied in spaced parallel relation by a tiebeam 25. These beam assemblies are basically of the same construction except for minor variations which will be noted in the following description. Only the beam assembly 10b is described in detail. Throughout the description, portions of the beam assembly 10b will be identified by reference numerals followed by the letter b." Corresponding parts of the beam assemblies 100 and 10c, when mentioned, bear the same numeral identification, but the identifying number is followed by the letter a if the part appears in the beam assembly 10a, and the letter c if' the part appears in the beam assembly 10c.

The beam assembly 10b includes two channel members 12b and 14b disposed in spaced and parallel relation. Welded between the channel members 1211 and 14b at the left end thereof, as viewed in FIG. 1, is an H-beam 16b. Welded between the same channel members at the right end thereof is an H-beam b. The H-beam 20b is masked by other structure in FIG. 1, but appears in FIGS. 2 and 3.

Referring to FIGS. 2 and 3, it will be noted that the H-beam 16b projects upwardly from between the channel members 12b and 14b a distance approximating the height of the channel members 12b and 14b. The H-beam 20b projects upwardly from the channel members 12b b and 14b a substantially greater distance than does the I-I-beam 16b.

The three H-beams 16a, 16b and provide a bed or platform across which the logs are rolled to the log carriage. As previously noted, when a log is to be rolled onto a log carriage, the carriage is stopped adjacent the left side of the deck assembly, as viewed in FIG. 1. The H-beams 16a, 16b and 16c present a jagged profile at the left ends of the beam assemblies 10a, 10b and 100 which may easily snag objects projecting from the carriage and, to minimize this possibility, the left ends of the beam assemblies are shielded by plates 18a, 18b and which reduce the jaggedness of the end profiles of the beam assemblies.

Welded to the uppermost surface of the I-I-beam 20b is an elongate chain guide 22b which, together with the H-beam 20b, extends to the right, as viewed in FIG. 1, beyond the ends of the channel members 12b and 14b. The chain guide 22b, and corresponding chain guides 22a and 220 for the beam assemblies 10a and 100, extend to the right, as viewed in FIG. 1, an arbitrary distance to a suitable location where logs are placed on the chain guides 22a, 22b and 22c for a leftward advance over the deck assembly.

The chain guide 22b is a channel element which faces upwardly and receives a replaceable wear strip 24b. The strip 24b is preferably a hardwood, such as oak, which resists the abrasive action of a link chain 26b drawn axially along the length of the chain guide. The wear strip 24b does not entirely fill the channel in the chain guide 22b whereby the chain 26b is only partially recessed in the chain guide 22b. Thus, the chain projects upwardly to an elevation above the side walls of the chain guide 22b. The chain 26b and the similarly mounted chains 26a and 26c associated with the beam assemblies 10a and 10c provide a traveling bed by which logs placed on the deck assembly are moved in the leftward direction, as viewed in FIG. 1.

To efiect this leftward advance, the chains 26a, 26b and 260 are driven by means of sprockets keyed to a shaft 32 extending transversely over the beam assemblies 10a, 10b and 106 and extending through a gap between the described H-beams in each of these beam assemblies. The sprockets are identified by the reference numbers 30a, 30b and 30c and, being of conventional construction, are not illustrated and described in detail.

The shaft 32 is supported for rotation on the beam assemblies 10a, 10b and 10c by journal boxes 34, 36 and 38. The journal box 34 is affixed to the beam assembly 100 with the aid of a short bar 40 of channel stock welded to the outer face of the channel member 12a. The journal box 36 is affixed to the beam assembly 10b with the aid of a similar bar 42 welded to the channel member 14b. In similar fashion, the journal box 38 is affixed to the beam assembly 100 with the aid of a bar 44 welded to the channel member 14c of the beam assembly 10c.

The mechanism for rotating the shaft 32 is mounted to the beam assembly 10c and comprises brackets 46 and 48 welded to the beam assembly 100 to support a gear reducer 50 therebetween. The gear reducer 50 has driving engagement with a splined section 52 of the shaft 32. Power derived from a rotary hydraulic motor 56 is supplied to the gear reducer 50 by means of a coupler 54. The motor 56 is supported against rotation so that a torque can be applied through the gear reducer 50 by means of a torque arm 58 bearing against the bar 44 between spaced guide posts 60 and 62 welded to the bar 44. The torque arm 58 provides a chain drive in only one direction, this being a movement of the upper portions of the chains toward the shaft 32. The chains return to the right under the beam assemblies 10a, 10b and 10: to complementary sprockets, not shown, which are mounted adjacent the extreme right ends of the chain guides 22a, 22b and 220.

The return path under the beam assemlbly 10b, for example, extends under the I-I-beam 20b and between the channel members 12b and 14b. The channel members 12b and 14b project downwardly below the lowermost extent of the H-beam 20b,

thus providing a passage between the tie-beam 25 and the H- beam b passing thereover. A similar return passage exists under the channel members 10a and 100.

The portions of the deck assembly above described are of a conventional nature and merely provide a background for describing the invention to which this application is directed.

In the use of the described deck assembly the chains 26a, 26b and 260 are operated intermittently, as required, to advance logs from right to left, as viewed in FIG. I, for ultimate rolling onto a log carriage. The carriage is stopped beside the deck assembly only periodically to receive a single log and, at times when the log carriage is not positioned adjacent the deck assembly, some means is needed to interrupt the advance of additional logs toward the H-beams 16a, 16b and 160. In addition, some means is needed to selectively transfer individual logs over the H-beams 16a, 16b and 166 to the log carriage so that only one log will be loaded at a time.

The transfer mechanism of the present invention satisfies these needs. The mechanism comprises three cradle members 70a, 70b and 700 fixedly mounted to a shaft 72 spaced from and extending parallel to the shaft 32. As appears in FIG. 11, the shaft 72 is supported for rotation by means of journal boxes 74, 76 and 78 fastened to mounting plates, not shown, welded between the channel members, such as 1217 and 14b, of the beam assemblies 10a, 10b and 10c. A detailed illustration of the cradle member 70]) appears in FIGS. 2 and 3 and the cradle members 7012 and 700 duplicate the cradle member 70b in all material respects.

The cradle member 70b comprises two angularly disposed arms 75 and 77 connected by an integral web portion having a concave margin 79. The margin 79 provides an are for cradling a log, as shown in FIG. 2. The arms 75 and 77 which extend radially outwardly from the shaft 72, terminate with elevated bosses 80 and 82, respectively, which project outwardly from the concave margin 79 and which retard sliding or rolling movement ofa log out of the cradle.

Spaced upwardly from the cradle member 70b, as viewed in FIG. 1, and welded to the shaft 72, are spaced crank arms 84a and 84b separated by a spacer 87 which cooperates with the shaft 72 to hold the arms 84a and 84b in parallel relation. The arms 34a and 84b pivotally support a pivot pin 86 in radially spaced relation from the shaft 72.

Fixed to the pin 86 is the piston rod 88 of a bidirectional hydraulic motor 90. Hydraulic power is supplied to the motor 90 through ports 92 and 94.

As hydraulic fluid is supplied to the port 92, the cradle members 70a, 70b and 700 are pivoted in the counterclockwise direction, as viewed in FIG. 2, to the position illustrated in FIG. 3. As power is supplied to the port 94, the cradle members 70a, 70b and 70c are returned in the clockwise direction to the position illustrated in FIG. 2.

The motor 90 is pivotally attached to the beam assembly 10b by means ofa pivot pin 96 journaled at one end in a suitable aperture in a bearing plate 97 welded to the bar 42. At its opposite end, the pin 96 is journaled in an aperture located in a plate 98 supported in spaced relation to the bar 42 by a plate 100 welded to the bar 427 The plate 98 is reinforced by means of a gusset 102 welded against the bar 42.

In the operation of the present invention, logs are advanced to the left, as viewed in FIGS. 2 and 3, by the chains 26a, 26b and 260. When a first log reaches the cradle members 70a, 70b and 70:, the bosses 80 thereon retard continued leftward movement of the first log out of the cradle members. Assuming logs are being intermittently placed on the deck assembly, as available, a second log ultimately bumps against the first log, occupying the position shown in FIG. 2. Additional logs may then accumulate behind the first log. As appears in FIG. 2, the first log is effectively disengaged from the chains 26a, 26b and 260, but the second log remains on the chains. While the logs for which this equipment is designed are quite massive, the frictional drag between the chains 26a, 26b and 26c and other logs advanced toward the cradle behind the first log is not sufficient to push the first log out of the cradle assem hly.

When, subject to the control of an operator, the cradle members 70a, 70b and 700 are simultaneously pivoted in the counterclockwise direction by means of the motor 90, the bosses 82 of the cradle members 70a, 70b and 700 dig into the right side of the single log on the cradle members and assist the cradle members to discharge the log to the left, as viewed in FIG. 3, causing the log to roll over the H-beams 16a, 16b and 16c and onto a waiting carriage. It will be noted that the transfer of the logs is facilitated by the elevation drop between the i-I-beams 2th, 2012 and 200 and the H-beams 16a, 16b and Me, which permits gravity to assist the motor 90.

An important feature of the present invention is the means by which the discharge of more than one log is prevented at any one time. Associated with each of the cradle members 70a, 70b and 700 is a downwardly depending arcuate bumper 106 integral with the arm 77 of the cradle member. The arms 77 of the cradle members 70a, 70b and 700 support the arcuate bumpers 106 a radial distance from the shaft 72 sufficient to permit the bumpers 106 to pass alongside the chain drive shaft 32. The bumper members 106 are so located axially along the shaft 72 that in passing alongside the shaft 32 they do not bump against the chains 26a, 26b and 26c. To keep the bumper members 106 radially close to the shaft 72 and at the same time avoid interference with the shaft 32, the bumper members N6 have a curvature which is substantially circumferential with respect to the shaft 72.

The juncture between the bumper 106 and the arm 77 of each of the cradle members 76a, 70b and 70c defines a bight 108 in which the shaft 32 is received. An abutment 104 fixed to the beam assembly 10b limits clockwise travel of the crank arms 84a and 84b so that rubbing contact between the cradle members 70a, 70b and 70:: and the shaft 32 is prevented. The bights 108 associated with the cradle members permit the eradle members to be pivoted in the clockwise direction, as viewed in FIG. 2, to a position in which the bosses 82 associated with the cradle members are recessed below the upper levels of the chains 26a, 26b and 26c. This allows a log to roll freely into the cradle without interference from the bosses 32.

By providing the bumpers 106 on the cradle members 70a, 70b and 700, it is apparent that, as one log is discharged from the cradle members, a second log is blocked by the bumpers 106 from a following movement into the cradle members and, at the same time, the following log is prevented from moving under the arms 77 of the cradle members, thereby maintaining a clearance so that the cradle members may be returned in the clockwise direction to receive the following log. The curved outer margins of the bumper members 106 also preclude hooking of the bumper members on any following log. The bumper members 106 thus assure that the cradle defined by the cradle members 70a, 70b and 70c will receive and discharge only one log at a time and that following logs will not be able to reach a position where the operation of the cradle members can be jammed.

The cradle members are so designed that, as the cradle members are pivoted to discharge an individual log, the log passes directly over the journal boxes for the shaft 72. Since logs are not uniformly round and often have projecting knots, it is preferred to protect the journal boxes from direct contact with the logs. With reference to the beam assembly 10b, four upwardly projecting posts 110b, 112b, 114b and l16b shield the journal box 76 from contact with the logs passed thereover. As appears in FIGS. 2 and 3, the top surfaces of these posts are sloped to conform to the difference in elevation between the beams 16b and 20b. As appears in FIG. 1, similar posts surround the journal boxes 74 and 78.

By mounting the cradle members 70a, 70b and 70c with the control shaft 72 in the manner described, a number of benefits result. By mounting the control shaft 72 closely adjacent the chain drive shaft 32, it is possible for the bumper members R06 to stop following logs while they remain on the drive chains. As a result, the following logs are stopped at a position where the drive chains are still capable of moving such following logs toward the cradle members after the cradle members have returned to the position illustrated in H0. 2. Since the bumpers 106 are curved about the axis of the shaft 72, the cradle members can be pivoted to discharge a log and then returned to receive a following log without forcing following logs to roll backwardly, and thus with a minimum of torque on the shaft 72. An additional benefit from the present invention is that the entire length of the drive chains is used beneficially. In other words, the drive chains are efiective to move logs all the way up to and over the sprockets on the shaft 32. A further benefit results from the ease with which the cradle members and their control shaft 72 may be detached from the deck assembly for repair or replacement. For such detachment, all that is required is to release the journal boxes 74, 76 and 78 and remove the pivot pin 96 which anchors the motor 90 to the beam assembly b. Other advantages and benefits will occur to those skilled in the art.

Having thus described by invention, I claim:

1. Apparatus of the class described comprising: conveyor means to convey loads in a first direction, said conveyor means including a shaft transverse to said first direction and over which said loads are conveyed, a cradle assembly to receive and transfer loads from said conveyor means, means supporting said cradle assembly for rotation about a first axis transverse to said first direction and spaced from said shaft, motive means operatively connected to said cradle assembly to rotate said assembly about said first axis between first and second positions, said assembly adapted to support a load received from said conveyor means in said first position and to discharge said supported load in said second position, a bumper member and means fixedly mounting said bumper member to said cradle assembly in spaced relation to said first axis, the space between said bumper member and said first axis exceeding the space between said shaft and said first axis, said mounting means defining a bight with said bumper member and said cradle assembly, said bight adapted to receive said shaft in said first position, said cradle assembly supporting said bumper member above said shaft to block the movement of loads over said shaft in said first direction when said cradle assembly is in said second position, said bumper member being moved outside the path of said loads by rotation of said cradle assembly to said first position.

2. The apparatus of claim 1 including a load supporting deck over which said conveyor means moves said loads, said motive means comprising motor means connected between said deck and said cradle assembly.

3. The apparatus of claim 1 in which said cradle means comprises angularly disposed arm portions projecting radially from said first axis and web means having an arcuate margin extending between said arm portions to define a load receiving cradle, said means mounting said bumper member mounting said bumper member adjacent the radially outer end of one of said arm portions.

4. The apparatus of claim 3 in which said bumper member has a margin extending circumferentially of said first axis. 

1. Apparatus of the class described comprising: conveyor means to convey loads in a first direction, said conveyor means including a shaft transverse to said first direction and over which said loads are conveyed, a cradle assembly to receive and transfer loads from said conveyor means, means supporting said cradle assembly for rotation about a first axis transverse to said first direction and spaced from said shaft, motive means operatively connected to said cradle assembly to rotate said assembly about said first axis between first and second positions, said assembly adapted to support a load received from said conveyor means in said first position and to discharge said supported load in said second position, a bumper member and means fixedly mounting said bumper member to said cradle assembly in spaced relation to said first axis, the space between said bumper member and said first axis exceeding the space between said shaft and said first axis, said mounting means defining a bight with said bumper member and said cradle assembly, said bight adapted to receive said shaft in said first position, said cradle assembly supporting said bumper member above said shaft to block the movement of loads over said shaft in said first direction when said cradle assembly is in said second position, said bumper member being moved outside the path of said loads by rotation of said cradle assembly to said first position.
 2. The apparatus of claim 1 including a load supporting deck over which said conveyor means moves said loads, said motive means comprising motor means connected between said deck and said cradle assembly.
 3. The apparatus of claim 1 in which said cradle means comprises angularly disposed arm portions projecting radially from said first axis and web means having an arcuate margin extending between said arm portions to define a load receiving cradle, said means mounting said bumper member mounting said bumper member adjacent the radially outer end of one of said arm portions.
 4. The apparatus of claim 3 in which said bumper member has a margin extending circumferentially of said first axis. 